Powerful Single & Multiple Select Library – tail.select
tail.select is a rewritten version of the jQuery tail.select plugin that can be used to beautify & enhance the default select box with no dependency.
JavaScript & CSS multiple select
Customizable Select Box & Input Field Enhancement Library – Choices.js
Choices.js is a vanilla JavaScript plugin for creating customizable select inputs with multi select and autocomplete support.
Lightweight Customizable Select Box Enhancement Library – Selectr
Selectr is a JavaScript library that converts the normal select box into a searchable, ajax-enabled dropdown selector with custom styling and events.
Create Dual List Box With Pure JavaScript – multi.js
multi.js is a lightweight JavaScript plugin that transforms the normal multiple select into a filterable/searchable dual list box interface for easier option selection.
Multiselect Dropdown List With Checkboxes – multiselect.js
multiselect.js is an unobtrusive JavaScript plugin that converts the native select box into a multi-select control with checkboxes and check all button.
Multiple Select Enhancement Library – Select7
Select7 is a vanilla JavaScript plugin to create a user-friendly multi-select control from a regular select element.
Multi-select Dropdown Component For JavaScript – slim-select
slim-select is a small and dependency-free JavaScript plugin for creating a searchable, multi-selectable dropdown list from a regular select element.
Pretty Select Box Replacemenet With Pure JavaScript – tastySelect
tastySelect is a JavaScript plugin to create animated, pretty nice, multi-select dropdown list without any dependencies.
Pure JS Dual List Box Component
A pure JavaScript plugin that converts the normal select box into a searchable dual list box where the users are able to move options between two selection panels.
Elegant Multi-Select Component With Autocomplete – SelectPure
SelectPure is a pure JavaScript (es6) library to create elegant single or multiple select controls with support for autocomplete and dynamic data rendering.